3129
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 4800
- Proper Divisor Sum (Aliquot Sum)
- 1671
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 1776
- Möbius Function
- -1
- Radical
- 3129
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 110
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers that are the sum of 5 positive 5th powers.at n=48A003350
- Related to representations as sums of Fibonacci numbers.at n=46A006133
- List of pairs of primes in reverse order, starting at 1.at n=5A007796
- Coordination sequence T2 for Zeolite Code STI.at n=38A008235
- Coordination sequence T1 for Zeolite Code -ROG.at n=42A009859
- Coordination sequence T1 for Zeolite Code CGS.at n=41A027365
- Expansion of 1/((1-3x)(1-4x)(1-6x)(1-8x)).at n=3A028033
- Odd composite numbers n such that the digit sum of n equals digit sum of sum of its prime factors (counted with multiplicity).at n=38A036923
- a(n)=(s(n)+2)/8, where s(n)=n-th base 8 palindrome that starts with 6 (in base 8), written in decimal digits.at n=25A043070
- Numbers having four 0's in base 5.at n=7A043352
- Numbers k such that the string 5,6 occurs in the base 9 representation of k but not of k-1.at n=42A044302
- Numbers n such that string 2,9 occurs in the base 10 representation of n but not of n-1.at n=34A044361
- Numbers n such that string 1,2 occurs in the base 10 representation of n but not of n+1.at n=35A044725
- Numbers n such that string 2,9 occurs in the base 10 representation of n but not of n+1.at n=34A044742
- If decimal expansion of n is ab...d, a(n) = a^a + b^b +...+ d^d.at n=25A045503
- If decimal expansion of n is ab...d, a(n) = a^a + b^b + ... + d^d (ignoring any 0's).at n=25A045512
- a(n) = Sum{a(k): k=0,1,2,...,n-4,n-2,n-1}; a(n-3) is not a summand; initial terms are 0,3,4.at n=13A049863
- Polynomial extrapolation of 2, 3, 5, 7, 11, 13, 17.at n=10A061166
- Numbers k that, when expressed in base 6 and then interpreted in base 8, give a multiple of k.at n=9A062937
- Composites for which the row of the prime-composite array (A063173) includes the leftmost element of both a zero-only antidiagonal and a zero-only diagonal(A067681).at n=25A063176